Struts

Uploading files in StrutsStruts has default interceptor (in-build interceptor) for uploading files, however not that these files will get stored in temporary directory they should be processed and stored in permanent location. (Refer: Default Interceptors in Struts)

What are Interceptors?
Interceptors are used for performing operations like Validation, file upload, exception handling etc.

Advantages of Interceptors:Separation of Concerns, If we need to remove any of the concerns like validation or exception handling etc.. We can remove them from struts.xml without disturbing the application.

Struts 2 provide a set of default interceptors (default interceptors), we can also create and implement our own interceptors. Creating and implementing own interceptors are known as Custom Interceptors.

Lets see an example for custom interceptors, We are going to check the time for the process.

What are Interceptors?
Interceptors are used for performing operations like Validation, file upload, exception handling etc.

Advantages of Interceptors:Separation of Concerns, If we need to remove any of the concerns like validation or exception handling etc.. We can remove them from struts.xml without disturbing the application.

Default Interceptors:Struts 2 has some in-built default interceptors, also we can build our own custom interceptors. In this post, we are going to explore default interceptors.

Interceptor

Description

alias

Parameters to have different name aliases

checkbox

Managing checkboxes to check which is checked and unchecked

conversionError

Error message when converting string to parameter value

createsession

creating new session

execAndWait

Sends intermediary waiting page when process executes background

Exception

Throwing exceptions

fileupload

for uploading files

logger

simple logging by displaying name

params

request parameters on the action

Prepare

Pre-preocessing works

timer

Shows how long the it takes for action to execute

token

checks for valid token to prevent duplication

validation

provides validation

Lets see an example,

Lets check the “timer” interceptor to check the time taken for executing the action.